1. Field of Invention
The present invention relates to a digital-analog converter, a circuit board, an electronic device, and a liquid crystal display device.
2. Description of Related Art
A well-known digital-analog converter in the form of a voltage dividing circuit has serially connected resistors and outputs an analog signal based on an input digital signal. For example, searching the PATOIS of Japan Patent Information Organization with the search formula, ((D/A+digital-analog+(digital*analog))*(C+converter))+(drive*circuit)*resi stor*(serial+parallel)*(potential+voltage)* liquid crystal, identified 98 items. In particular, Japanese Unexamined Patent Publication No. 5-181436 was found which discloses a digital-analog converter that has serially connected resistors as discussed above.
According to a conventional digital-analog converter like this, since a voltage dividing circuit is constructed by serially-connected resistors, as shown for example in FIG. 11, it is necessary to provide not only many resistors, but also many switches for the respective resistors. Further, since a current always flows through the serially-connected resistors, power consumption is large. These are problems of the conventional digital-analog converter.